Decorative sheet and method for manufacturing decorative sheet

Abstract

Provided is a decorative sheet having low gloss and excellent design, fingerprint resistance, high durability, processability, and water resistance. To this end, a raw fabric layer (2), a water-resistant protective layer (9), and a surface protective layer (5) are laminated in this order, the surface protective layer (5) is formed with a concavo-convex shape having ridge-like protruding ridges (5b) on the surface thereof, the ratio RSm / Ra of the surface roughness index RSm to the surface roughness index Ra in the concavo-convex shape of the surface protective layer (5) is in the range of 10-300, the main material of the surface protective layer (5) is an ionizing radiation curable resin, the ionizing radiation curable resin contains a repeating structure-containing trifunctional acrylic resin as a main component, and the number of repetitions of the repeating structure is at least 3.

Description

Decorative sheet and method for manufacturing decorative sheet

[0001] The present invention relates to a decorative sheet used for the surface decoration of the interior and exterior decoration of buildings, fittings, furniture, fixtures, flooring materials, etc., and a method for producing the decorative sheet.

[0002] Decorative sheets are widely used in the aforementioned buildings to impart design and durability to their surfaces by laminating them with adhesives or the like to the surfaces of wood, wood boards, metal plates, non-flammable boards, paper substrates, or resin substrates to form decorative panels. Regarding the design, various designs are selected depending on the requirements and applications, from those with patterns such as wood grain or stone grain formed using various printing methods to plain surfaces without any patterns. Similarly, the glossiness of the surface is also an important factor in terms of design, and is selected depending on the requirements and applications, from a high gloss like a mirror to a low gloss with no reflections at all.

[0003] As mentioned above, durability is an important function of decorative sheets, along with design. Durability is a comprehensive assessment of scratch resistance, stain resistance, and whether these properties can be maintained over a long period of time. Requirements vary depending on the environment and circumstances in which the decorative sheet is used, but decorative sheets with consistently high performance are always required. To impart durability, a surface protective layer is typically formed on the outermost surface of the decorative sheet. Furthermore, in order to adjust the gloss mentioned above, and particularly to achieve a low gloss, it is common to add a gloss adjuster (matt additive) to the surface protective layer.

[0004] Furthermore, decorative sheets are generally subjected to processes such as cutting and bending to form decorative panels and decorative materials, and therefore it is preferable that the decorative sheets have processability that can withstand these processes. Furthermore, decorative sheets are required to be water resistant to prevent deterioration due to water penetration through the sheet surface when used in wet areas. As such, decorative sheets that take into consideration design (low gloss), scratch resistance, and stain resistance have been proposed, for example, in Patent Document 1.

[0005] Japanese Patent Application Laid-Open No. 2019-119138

[0006] In recent years, due to the expansion of applications of decorative sheets and the increasing sophistication of consumer awareness of quality, decorative sheets that have low gloss, fingerprint resistance, scratch resistance, stain resistance, and bendability are in demand. Furthermore, when decorative sheets are used in wet areas such as kitchens, toilets, modular baths, vanities, and window frames, water resistance is required.

[0007] To meet the above requirements, one method of reducing gloss is to add a high concentration of gloss adjuster to roughen the surface, but adding a large amount can cause the following problems: (1) Fingerprint stains become difficult to remove, resulting in a decrease in fingerprint resistance. (2) The gloss adjuster is detached during a scratch resistance test, resulting in a decrease in scratch resistance. (3) Stains become difficult to remove, resulting in a decrease in stain resistance. (4) When bending, the gloss adjuster triggers whitening, resulting in a decrease in bending workability.

[0008] In addition, one method of imparting water resistance is to add a highly cross-linked component as a secondary component to the surface protective layer, but adding a large amount of this component causes the following problems: (1) The ridge-like uneven structure becomes rough, increasing gloss. (2) While the highly cross-linked component increases hardness, it also reduces bending workability.

[0009] In order to solve the above problems, the present invention aims to provide a decorative sheet that has low gloss and excellent design properties, as well as fingerprint resistance, high durability (especially scratch resistance and stain resistance), processability, and water resistance.

[0010] The inventors have found that by optimizing the uneven shape of the surface protective layer to achieve low gloss, and by conducting repeated experiments to find the necessary structural elements for the material used in the surface protective layer, it is possible to provide a decorative sheet that exhibits low gloss, fingerprint resistance, high durability (especially scratch resistance and stain resistance), processability, and water resistance.

[0011] A decorative sheet according to one embodiment of the present invention comprises a base layer, a water-resistant protective layer, and a surface protective layer laminated in this order, the surface protective layer having an uneven shape with ridge-like protruding portions formed on its surface, the ratio RSm / Ra of the surface roughness index RSm of the uneven shape of the surface protective layer to the surface roughness index Ra is in the range of 10 or more and 300 or less, the surface protective layer is mainly made of an ionizing radiation curable resin, the ionizing radiation curable resin is a trifunctional acrylic resin whose main component is a repeating structure, and the number of repetitions of the repeating structure is 3 or more.

[0012] Furthermore, a decorative sheet manufacturing method according to another aspect of the present invention is a decorative sheet manufacturing method according to the above aspect, characterized in that the surface of the applied ionizing radiation curable resin is irradiated with light having a wavelength of 200 nm or less, and then irradiated with ionizing radiation or UV light having a wavelength longer than the light having a wavelength of 200 nm or less, thereby forming a surface protective layer having ridge-like protruding portions.

[0013] According to one aspect of the present invention, a decorative sheet can be provided that has low gloss, fingerprint resistance, scratch resistance, stain resistance, bendability, and water resistance.

[0014] Fig. 1 is a cross-sectional view schematically showing an example of a decorative sheet according to one embodiment of the present invention. Fig. 2 is a cross-sectional view schematically showing an example of a surface protective layer of a decorative sheet according to one embodiment of the present invention. Fig. 3 is a plan view photograph showing an example of the surface of a surface protective layer of a decorative sheet according to one embodiment of the present invention. Fig. 4 is a schematic cross-sectional view illustrating the cross-sectional shape of a ridge portion according to one embodiment of the present invention. Fig. 5 is a schematic view illustrating the change over time in the amount of irradiation light of each irradiation light in the manufacturing process of a decorative sheet according to one embodiment of the present invention.

[0015] The configuration of a decorative sheet according to an embodiment of the present invention will be described below with reference to the drawings. The drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, and the like differ from reality. Furthermore, the embodiments shown below exemplify configurations that embody the technical concept of the present invention, and various modifications can be made to the technical concept of the present invention within the technical scope defined by the claims.

[0016] (Configuration) As shown in Figure 1, the decorative sheet 1 of this embodiment is configured by laminating a pattern layer 3, an adhesive layer 7 (e.g., a heat-sensitive adhesive layer, an anchor coat layer, and a dry lamination adhesive layer), a transparent resin layer 4, a water-resistant protective layer 9, and a surface protective layer 5 in this order on one surface, or the front side, of a raw fabric layer (substrate layer) 2. Furthermore, a concealing layer 8 and a primer layer 6 are provided in this order on the other surface, or the back side, of the raw fabric layer 2. The pattern layer 3, adhesive layer 7, transparent resin layer 4, concealing layer 8, and primer layer 6 do not necessarily have to be provided. As shown in Figure 1, the decorative sheet 1 according to one embodiment of the present invention is bonded to a substrate B to form a decorative material 11. The substrate B is not particularly limited, and may be configured, for example, from a wood board, an inorganic board, a metal plate, a composite board made of multiple materials, or the like.

[0017] <Raw Fabric Layer 2> The raw fabric layer 2 can be made of any material selected from, for example, paper, synthetic resin, synthetic resin foam, rubber, nonwoven fabric, synthetic paper, metal foil, etc. Examples of paper include tissue paper, titanium paper, and resin-impregnated paper. Examples of synthetic resins include polyethylene, polypropylene, polybutylene, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, and acrylic. Examples of rubber include ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene-styrene block copolymer rubber, styrene-butadiene-styrene block copolymer rubber, and polyurethane. Examples of nonwoven fabrics include organic and inorganic nonwoven fabrics. Examples of metals for the metal foil include aluminum, iron, gold, and silver.

[0018] When an olefin-based resin is used as the raw fabric layer 2, the surface of the raw fabric layer 2 is often in an inactive state, so it is preferable to provide a primer layer 6 between the raw fabric layer 2 and the substrate B. In addition, in order to improve the adhesion between the raw fabric layer 2 made of an olefin-based material and the substrate B, the raw fabric layer 2 may be subjected to a surface modification treatment such as corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, or dichromate treatment.

[0019] The primer layer 6 can be made of the same material as the pattern layer 3, which will be described later. Since the primer layer 6 is applied to the back surface of the decorative sheet 1, and considering that the decorative sheet 1 will be wound into a web, an inorganic filler may be added to the primer layer 6 to avoid blocking and improve adhesion with the adhesive. Examples of inorganic fillers include silica, alumina, magnesia, titanium oxide, and barium sulfate. Considering printing workability and cost, the thickness of the base fabric layer 2 is preferably in the range of 20 μm to 250 μm.

[0020] <Picture Layer 3> The picture layer 3 is a layer of picture printing applied to the base layer 2 using ink. Examples of ink binders include soluble nitrocellulose, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, and polyester, either alone or modified. The binder may be aqueous, solvent-based, or emulsion-based, and may be a one-component type or a two-component type that includes a curing agent. Furthermore, a method may be used in which a curable ink is cured by exposure to ultraviolet light or electron beams. The most common method is to use a urethane-based ink and cure it with isocyanate. In addition to the binder, the picture layer 3 may contain, for example, pigments, colorants such as dyes, extender pigments, solvents, and various additives, all of which are commonly found in inks. Examples of versatile pigments include condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, and pearl pigments such as mica.

[0021] Furthermore, apart from applying ink, it is also possible to apply designs to the pattern layer 3 by vapor deposition or sputtering of various metals. In particular, it is preferable that a light stabilizer be added to the ink, as this can suppress deterioration of the decorative sheet 1 itself caused by light degradation of the ink, thereby extending the life of the decorative sheet 1.

[0022] <Adhesive Layer 7> The adhesive layer 7 is also referred to as a heat-sensitive adhesive layer, anchor coat layer, or dry lamination adhesive layer. The resin material for the adhesive layer 7 is not particularly limited, but may be appropriately selected from acrylic, polyester, polyurethane, epoxy, and other resin materials. An ethylene-vinyl acetate copolymer resin adhesive, for example, may also be used as the resin material for the adhesive layer 7. The coating method can be selected appropriately depending on the viscosity of the adhesive, but gravure coating is typically used. The adhesive is applied to the upper surface of the design layer 3 by gravure coating, and then laminated with the transparent resin layer 4. The adhesive layer 7 can be omitted if sufficient adhesive strength is obtained between the transparent resin layer 4 and the design layer 3.

[0023] <Transparent Resin Layer 4> An olefin-based resin is preferably used as the resin material of the transparent resin layer 4. Examples of the olefin-based resin include polypropylene, polyethylene, polybutene, and the like, as well as α-olefins (e.g., propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, Examples of the copolymer include a homopolymer or copolymer of two or more types of α-olefins (e.g., ethylene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc.), and a copolymer of ethylene or an α-olefin with another monomer, such as an ethylene-vinyl acetate copolymer, an ethylene-vinyl alcohol copolymer, an ethylene-methyl methacrylate copolymer, an ethylene-ethyl methacrylate copolymer, an ethylene-butyl methacrylate copolymer, an ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, or an ethylene-butyl acrylate copolymer.

[0024] Furthermore, in order to improve the surface strength of the decorative sheet 1, it is preferable to use highly crystalline polypropylene as the resin for the transparent resin layer 4. Note that, if necessary, various additives such as heat stabilizers, light stabilizers, antiblocking agents, catalyst scavengers, colorants, light scattering agents, and gloss adjusters can also be added to the transparent resin layer 4. Generally, phenol-based, sulfur-based, phosphorus-based, hydrazine-based, and other heat stabilizers are added, and hindered amine-based, and other light stabilizers are added, in any combination.

[0025] <Water-Resistant Protective Layer 9> The resin material for the water-resistant protective layer 9 is not particularly limited, and for example, an ionizing radiation curable resin or a thermosetting resin is suitably used. As the ionizing radiation curable resin, for example, known materials such as various monomers and commercially available oligomers can be used, and for example, it is preferable to use polyfunctional monomers such as pentaerythritol triacrylate (PET3A), pentaerythritol tetraacrylate (PET4A), trimethylolpropane triacrylate (TMPTA), dipentaerythritol hexaacrylate (DPHA), etc., polyfunctional oligomers such as Shikoh UV-1700B (manufactured by The Nippon Synthetic Chemical Industry Co., Ltd.), or mixtures thereof.

[0026] The thermosetting resin is preferably formed by thermally curing a polymer containing a carboxyl group described below with an epoxy compound or a carbodiimide compound. The polymer containing a carboxyl group is not particularly limited, but may be used to impart mechanical properties by elongating the molecular structure, and may be appropriately selected from various acrylic polymers, polyesters, polyethers, polycarbonates, polyurethanes, etc.

[0027] Epoxy group is a general term for compounds having a three-membered ring ether, oxacyclopropane (oxirane), in their structural formula. They have excellent reactivity and are used in a variety of applications. Epoxy compounds also have the effect of inhibiting hydrolysis, a major problem for major general-purpose resins, by capturing the acid in the polymer that acts as a catalyst for the decomposition reaction, and are therefore effective in improving water resistance. As with the above, epoxy compounds are not particularly limited, but include sorbitol polyglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, pentaerythritol polyglycidyl ether, cresol novolac epoxy emulsion, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, Examples of suitable carbodiimide compounds include 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, terephthalic acid diglycidyl ester, phthalic acid diglycidyl ester, hydrogenated phthalic acid diglycidyl ester, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, phenol (EO) 5 glycidyl ether, p-tert-butylphenyl glycidyl ether, dibromophenyl glycidyl ether, lauryl alcohol (EO) 16 glycidyl ether, C12 and C13 mixed alcohol glycidyl ether, and N-glycidylphthalimide. A major example of a carbodiimide compound is "Denacol EX-830" manufactured by Nagase ChemteX Corporation.

[0028] Carbodiimides are functional groups represented by -N=C=N-, have excellent reactivity, and are used in a variety of applications. Like epoxy compounds, carbodiimide compounds are effective in improving water resistance because they have an inhibitory effect by capturing the acid in the polymer that catalyzes the decomposition reaction of resins. As with the above, carbodiimide compounds are not particularly limited, but include diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, N-3-dimethylaminopropyl-N'-ethylcarbodiimide, N-tert-butyl-N'-ethylcarbodiimide, N-cyclohexyl-N'-2-morpholinoethylcarbodiimide meso-p-toluenesulfonic acid, and N,N'-di-tert-butylcarbodiimide. A major carbodiimide compound product is "Carbodilite V-02-L2" manufactured by Nisshinbo Chemical Inc.

[0029] Furthermore, the resin constituting the waterproof protective layer 9 in this embodiment is preferably an acrylic copolymer having an acid value of 15 mgKOH / g or more, crosslinked with a curing agent. If the acid value is less than 15 mgKOH / g, the crosslink density after curing is low, which may result in reduced water resistance. The acrylic resin contained in the waterproof protective layer 9 is preferably an aqueous emulsion. If the acrylic resin contained in the top coat layer 15 is an aqueous emulsion, a resin coating with a high molecular weight is obtained, improving water resistance. The thickness of the waterproof protective layer 9 is preferably in the range of 2 μm to 10 μm. A film thickness of 2 μm or less will result in insufficient water resistance. Furthermore, if a film thickness is 10 μm or more, drying will be insufficient when using an aqueous emulsion, and sufficient performance is achieved at a thickness of 10 μm or less. Therefore, it is determined that a film thickness greater than this is not necessary due to cost considerations.

[0030] <Surface Protective Layer 5> The surface protective layer 5 has a core portion 5A and a ridge portion 5B that protrudes in a ridge-like shape from one side of the core portion 5A. This forms an uneven shape on the surface of the surface protective layer 5. Here, in the decorative sheet 1 according to this embodiment, "ridge-like" refers to a shape that is elongated and raised and linearly connected in a planar view. The ridge portion 5B may be curved or linear in a planar view, but is preferably curved from the viewpoint of fingerprint resistance of the surface of the decorative sheet 1. Furthermore, in the present disclosure, the ridge portion 5B refers to, for example, the portion from the lowest point to the tip of the uneven shape formed on the surface of the surface protective layer 5, and the core portion 5A refers to the portion of the surface protective layer 5 excluding the ridge portion 5B.

[0031] FIG. 2 is a cross-sectional view schematically illustrating a cross-section of the ridge portions 5B of the surface protective layer 5 (cross-section in the thickness direction of the surface protective layer 5), and FIG. 3 is a planar photograph illustrating the surface configuration of the surface protective layer 5. Here, FIG. 3 is a planar photograph obtained with a laser microscope (OLS-4000 manufactured by Olympus Corporation). As shown in the planar photograph of FIG. 3, the ridge portions 5B are elongated raised portions that are linearly connected in a planar view. As will be described later, the ridge portions 5B are formed by irradiating the surface of the ionizing radiation curable resin with light of a specific wavelength to cause the surface of the ionizing radiation curable resin to shrink.

[0032] The shape of such ridge portions 5B can be expressed by the ratio RSm / Ra of the surface roughness index RSm (μm) in the horizontal direction (the planar direction of the surface protective layer 5, the left-right direction in FIG. 2 ) to the surface roughness index Ra (μm) in the vertical direction (the depth direction of the ridge portions 5B, the thickness direction of the surface protective layer 5, the up-down direction in FIG. 2 ), and RSm / Ra is preferably 10 or more and 300 or less. More preferably, RSm / Ra is 10 or more and 250 or less. If RSm / Ra is less than 10, the shape of the ridge portions 5B is too fine, making it difficult to wipe off dirt and resulting in poor stain resistance. If RSm / Ra is greater than 300, the spacing between the ridge shapes is too wide, and low gloss is not achieved.

[0033] Furthermore, RSm / Ra is more preferably 50 or more and 200 or less. If RSm / Ra is within this numerical range, the spacing between the ridge shapes is appropriately wide, thereby improving affinity with water or detergents (water containing surfactants or alcohol). Therefore, if the decorative sheet has RSm / Ra within this numerical range, even if the surface of the decorative sheet becomes dirty, it is easy to wipe off the dirt using water or detergent. Furthermore, RSm / Ra is most preferably 80 or more and 150 or less. If RSm / Ra is within this numerical range, a commonly available commercially available cleaning sponge can easily penetrate between the ridge shapes, and even if the surface of the decorative sheet becomes dirty, it is easy to wipe off the dirt using a commonly available commercially available cleaning sponge. Here, Ra and RSm are measured values ​​when measured using a line roughness meter (in accordance with JIS B0601).

[0034] The cross-sectional shape of the ridge portions 5B in the thickness direction of the surface protection layer 5 may be a sine wave shape. Here, "sine wave shape" refers to a shape in which the line from the lowest point C of the ridge portions 5B to the highest point (vertex) D can be expressed as a sine wave, as shown in Figure 4. Furthermore, the shape between adjacent ridge portions 5B (valleys) may be a concave curved shape. In other words, the shape of the lowest point C of the ridge portions 5B may be a concave curved shape.

[0035] The mechanism by which the ridge portions 5B are formed is described below. When acrylate is irradiated with light having a wavelength of 200 nm or less as the first irradiation light, the acrylate can self-excite. Therefore, irradiating acrylate with light having a wavelength of 200 nm or less allows the acrylate to be crosslinked. Light having a wavelength of 200 nm or less penetrates the acrylate to a depth of several tens to several hundred nanometers. As a result, only the surface is crosslinked, and the underlying portion retains fluidity, resulting in the formation of a series of fine, wavy irregularities resembling fold wrinkles. Light having a wavelength of 200 nm or less is absorbed by oxygen in the atmosphere and significantly attenuated. Therefore, when processing acrylate, it is necessary to control the reaction atmosphere by introducing nitrogen gas. It is preferable to keep the residual oxygen concentration in the reaction atmosphere below 2000 ppm. More preferably, the residual oxygen concentration in the reaction atmosphere is below 1000 ppm.

[0036] In order to generate a concave-convex shape using the first irradiation light having a wavelength of 200 nm or less, the integrated light amount of the first irradiation light is 0.5 mJ / cm ２ More than 200mJ / cm ２ It is preferable that the integrated light amount is 1 mJ / cm or less. More preferably, ２ More than 100mJ / cm ２ More preferably, the integrated light amount is 3 mJ / cm or less. ２ More than 50mJ / cm ２ Most preferably, the integrated light amount is 5 mJ / cm or less. ２ 30mJ / cm or more ２ The cumulative light amount is 0.5 mJ / cm ２ If the amount of light is less than 200 mJ / cm, the curing shrinkage reaction is weak and the unevenness is not sufficiently formed, so that the gloss does not decrease. ２ If it is more than this amount, the cure shrinkage reaction becomes too strong and the surface condition deteriorates.

[0037] The first irradiation light, light with a wavelength of 200 nm or less, can be extracted using excimer VUV light. Excimer VUV light can be produced from a lamp of a rare gas or a rare gas halide compound. When high-energy electrons are externally applied to a lamp filled with a rare gas or a rare gas halide compound gas, a large number of discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites atoms of the discharge gas (rare gas), momentarily transforming them into an excimer state. When returning from this excimer state to the ground state, light is emitted in a wavelength range specific to that excimer.

[0038] The gas used in the excimer lamp may be any conventional gas that emits light of 200 nm or less. Examples of suitable gases include rare gases such as Xe, Ar, and Kr, and mixtures of rare gases such as ArBr and ArF with halogen gases. Excimer lamps have different wavelengths (center wavelengths), depending on the gas used, such as approximately 172 nm (Xe), approximately 126 nm (Ar), approximately 146 nm (Kr), approximately 165 nm (ArBr), and approximately 193 nm (ArF). However, considering the magnitude of the photon energy obtained and the difference between the wavelength and the bond energy of organic matter, it is preferable to use a xenon lamp, which emits excimer light with a center wavelength of 172 nm, as the light source. Furthermore, considering the cost of maintaining the equipment and the availability of materials, it is preferable to use a xenon lamp as the light source.

[0039] Because the first irradiation light, which has a wavelength of 200 nm or less, only reaches a depth of several tens to several hundreds of nm from the outermost surface of the acrylate, the interior of the surface protection layer 5 having the ridged portions 5B formed by irradiation with light of 200 nm or less is fluid, and further curing reaction is required. To cure the surface protection layer 5 after irradiation with light of 200 nm or less, ionizing radiation or UV light having a longer wavelength than the first irradiation light of 200 nm or less can be used as the second irradiation light. Note that in this embodiment, for example, after irradiation with the second irradiation light, third irradiation light may be irradiated with a different type of ionizing radiation from the second irradiation light or UV light having a longer wavelength than the second irradiation light. However, it is preferable to form the surface protection layer 5 having the ridged portions 5B by irradiating only two types of light, the first irradiation light and the second irradiation light. Here, the third irradiation light may be irradiated when the strength of the surface protection layer 5 is insufficient with only irradiation with the second irradiation light.

[0040] In order to cure the entire surface protection layer 5 by irradiation with the second irradiation light, the integrated light amount of the second irradiation light is set to 10 mJ / cm ２ More than 500mJ / cm ２ More preferably, the integrated light amount is 50 mJ / cm or less. ２ More than 400mJ / cm ２ More preferably, the integrated light amount is 100 mJ / cm ２ More than 300mJ / cm ２ The cumulative light amount is 10 mJ / cm or less. ２ If the amount of light is less than 200 mJ / cm 2 , the curing reaction is weak and sufficient strength cannot be imparted to the entire surface protective layer 5 , which tends to reduce scratch resistance. ２ If it is more than this amount, the curing reaction tends to be too strong, resulting in poor surface condition.

[0041] Furthermore, the integrated light amount of the second irradiation light is preferably greater than the integrated light amount of the first irradiation light. The integrated light amount of the second irradiation light is preferably 1.1 to 50.0 times the integrated light amount of the first irradiation light, and more preferably 5.0 to 30.0 times. If the integrated light amount of the second irradiation light is less than 1.1 times the integrated light amount of the first irradiation light, the curing reaction is weak and sufficient strength may not be imparted to the entire surface protective layer 5. If the integrated light amount of the second irradiation light is more than 50.0 times the integrated light amount of the first irradiation light, the curing reaction of the entire surface protective layer 5 may be too strong, resulting in deformation of the shape of the ridge portion 5B.

[0042] The change in the amount of irradiation light of the first irradiation light and the change in the amount of irradiation light of the second irradiation light will be described below with reference to Fig. 5. Fig. 5 is a diagram schematically showing the change in the amount of irradiation light of the first irradiation light and the change in the amount of irradiation light of the second irradiation light. Figs. 5(a), (c), (e), (g), and (i) are diagrams schematically showing the change in the amount of irradiation light of the first irradiation light. Figs. 5(b), (d), (f), (h), and (j) are diagrams schematically showing the change in the amount of irradiation light of the second irradiation light.

[0043] The irradiation light intensity of the first irradiation light may gradually increase over the course of irradiation time, as shown in FIG. 5( a), and then gradually decrease over the course of irradiation time. Alternatively, the irradiation light intensity of the first irradiation light may gradually decrease over the course of irradiation time, as shown in FIG. 5( c). Alternatively, the irradiation light intensity of the first irradiation light may gradually increase over the course of irradiation time, as shown in FIG. 5( e). Alternatively, the irradiation light intensity of the first irradiation light may gradually decrease over the course of irradiation time, as shown in FIG. 5( g), and then gradually increase over the course of irradiation time. Alternatively, the irradiation light intensity of the first irradiation light may be constant from the start of irradiation to the end of irradiation, as shown in FIG. 5( i).

[0044] The irradiation light intensity of the second irradiation light may gradually increase over the irradiation time as shown in FIG. 5( b), and then gradually decrease over the irradiation time. Alternatively, the irradiation light intensity of the second irradiation light may gradually decrease over the irradiation time as shown in FIG. 5( d). Alternatively, the irradiation light intensity of the second irradiation light may gradually increase over the irradiation time as shown in FIG. 5( f). Alternatively, the irradiation light intensity of the second irradiation light may gradually decrease over the irradiation time as shown in FIG. 5( h), and then gradually increase over the irradiation time. Alternatively, the irradiation light intensity of the second irradiation light may be constant from the start of irradiation to the end of irradiation as shown in FIG. 5( j).

[0045] In addition, in this embodiment, the irradiation form of the first irradiation light shown in Figures 5(a), (c), (e), (g), and (i) and the irradiation form of the second irradiation light shown in Figures 5(b), (d), (f), (h), and (j) can be used in appropriate combination. For example, the irradiation form of the first irradiation light shown in Figure 5(a) and the irradiation form of the second irradiation light shown in Figure 5(f) may be used in combination. Furthermore, the irradiation form of the first irradiation light shown in Figure 5(g) and the irradiation form of the second irradiation light shown in Figure 5(f) may be used in combination. Note that, when the RSm / Ra value is set to a more preferable range of 10 or more and 300 or less, it is preferable to use the irradiation form of the first irradiation light shown in Figure 5(c) in combination with the irradiation form of the second irradiation light shown in Figure 5(f).

[0046] As described above, the ridges 5B formed by irradiation with light having a wavelength of 200 nm or less have a finer structure than the unevenness formed by mechanical processing such as embossing on the surface of the surface protective layer 5. By forming such a fine unevenness on the surface of the surface protective layer 5, it is possible to improve fingerprint resistance while maintaining the matte finish of the surface of the decorative sheet 1.

[0047] The thickness of the surface protective layer 5 is preferably in the range of 2 μm to 20 μm. More preferably, the thickness of the surface protective layer 5 is in the range of 3 μm to 20 μm. Even more preferably, the thickness of the surface protective layer 5 is in the range of 5 μm to 15 μm. Most preferably, the thickness of the surface protective layer 5 is in the range of 5 μm to 12 μm. If the thickness of the surface protective layer 5 is less than 2 μm, the shaping by vacuum ultraviolet light does not penetrate deep enough, and low gloss cannot be achieved. Furthermore, if the thickness of the surface protective layer 5 is greater than 20 μm, processability decreases and whitening occurs when bending. Furthermore, the thickness of the surface protective layer 5 is preferably set so that the ratio of the thickness of the ridge portion 5B to the thickness of the core portion 5A (thickness of the ridge portion 5B / thickness of the core portion 5A) is 0.01 to 2.0, and more preferably 0.1 to 1.0. The thickness of the surface protective layer 5 refers to the distance in the thickness direction of the surface protective layer 5 from the position where it contacts the waterproof protective layer 9 to the highest point of the uneven shape. The thickness of the ridge portion 5B refers to the distance in the thickness direction of the ridge portion 5B from the lowest point of the uneven shape, i.e., from the upper surface of the core portion 5A to the highest point of the uneven shape.

[0048] Here, the design layer 3 and the surface protective layer 5 can be formed by various printing methods, such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing. Furthermore, since the surface protective layer 5 covers the entire surface of the front side of the raw fabric layer 2, it can also be formed by various coating methods, such as roll coating, knife coating, microgravure coating, and die coating. These printing or coating methods may be selected separately for each layer to be formed, or the same method may be selected and used for batch processing.

[0049] The design layer 3 and the surface protective layer 5 may be synchronized from the viewpoint of design. In the case of synchronization, it is necessary to form the surface protective layer 5 after forming the design layer 3, and therefore it is preferable to use a gravure printing method. Furthermore, the gravure printing method allows for relatively high speed processing, and is therefore advantageous in terms of cost and is preferable. Here, synchronization means that 50% or more, preferably 70% or more, and most preferably 90% or more of the area where the surface protective layer 5 is formed overlaps with the design portion of the design layer 3 in a planar view.

[0050] The thickness of the surface protective layer 5 can be adjusted by adjusting the coating amount in the printing method and coating method described above. The coating amount can be calculated by comparing the mass difference between a substrate (raw layer) with and without a surface protective layer formed thereon, using various printing and coating methods. The surface protective layer 5 is primarily made of an ionizing radiation-curable resin. Here, the term "primary material" refers to a content of 60 parts by mass or more, more preferably 70 parts by mass or more, and most preferably 80 parts by mass or more, per 100 parts by mass of the surface protective layer. The ionizing radiation-curable resin constituting the surface protective layer 5 can be any known material, such as various monomers or commercially available oligomers. For example, (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins can be used. The ionizing radiation-curable resin may be either an aqueous or non-aqueous (organic solvent-based) resin.

[0051] The main component of the ionizing radiation curable resin constituting the surface protective layer 5 is a trifunctional acrylate resin containing a repeating unit. Examples of trifunctional acrylate resins (acrylic resins) that can be used include trimethylolpropane triacrylate, glycerin triacrylate, isocyanurate triacrylate, and pentaerythritol triacrylate. Here, the term "main component" refers to a content of 60 parts by mass or more, more preferably 70 parts by mass or more, and most preferably 80 parts by mass or more, per 100 parts by mass of the constituting resin components. A bifunctional acrylate resin is undesirable because it results in an insufficient degree of crosslinking, resulting in reduced scratch resistance. A tetrafunctional or higher acrylate resin is undesirable because it results in an excessively high degree of crosslinking, resulting in reduced processability.

[0052] When gravure printing is used as the coating method for ionizing radiation curable resins, the preferred viscosity range is 10 mPa·s or more and 500 mPa·s or less, and the optimal viscosity range is 50 mPa·s or more and 300 mPa·s or less. Therefore, using trimethylolpropane triacrylate or glycerin triacrylate as the trifunctional acrylate resin is preferable because it is possible to keep the viscosity within the preferred or optimal viscosity range. Resins with skeletons that induce hydrogen bonding or π-π stacking often have high viscosities of 500 mPa·s or more, which is undesirable. Furthermore, organic solvents or low-viscosity bifunctional acrylate resins can be added to adjust the viscosity. However, from the perspective of environmental impact, it is preferable not to use organic solvents. Adding large amounts of bifunctional acrylate resins is undesirable because scratch resistance decreases. Therefore, when a bifunctional acrylate resin is added to a trifunctional acrylate resin for use, the content of the bifunctional acrylate resin is preferably in the range of 10% by mass or more and 30% by mass or less of the content (mass) of the trifunctional acrylate resin, and more preferably in the range of 15% by mass or more and 20% by mass or less.

[0053] The repeating structure is preferably any one of an ethylene oxide (EO) structure, a propylene oxide (PO) structure, and an ε-caprolactone (CL) structure. More preferably, the repeating structure is ethylene oxide or propylene oxide. The ethylene oxide structure, the propylene oxide structure, and the ε-caprolactone structure are preferred because their molecules are freely rotatable and highly flexible, and therefore the molecules are easily folded by light with a wavelength of 200 nm or less, easily forming a fine uneven shape. Furthermore, the repeating number of this repeating structure is 3 or more. More preferably, it is 3 to 30, and most preferably, it is 3 to 20. If the repeating number is 2 or less, the ionizing radiation curable resin constituting the surface protective layer 5 does not shrink sufficiently when irradiated with vacuum ultraviolet light (VUV light), and the surface protective layer 5 does not have a low gloss. If the repeating number is more than 30, the crosslinking density decreases, and the scratch resistance of the surface protective layer 5 deteriorates.

[0054] The number of repetitions of the repeating structure can be analyzed using MALDI-TOF-MS. The ionizing radiation curable resin constituting the surface protective layer 5 may have a molecular weight distribution. If there is a molecular weight distribution, the number of repetitions is set to the number of repetitions corresponding to the molecular weight having the strongest peak in the MALDI-TOF-MS mass spectrum. The surface protective layer 5 may contain particles. A uniform surface can be formed by adding particles of an optimal particle size and content. Examples of particles that can be used include organic materials such as PE wax, PP wax, and resin beads, and inorganic materials such as silica, glass, alumina, titania, zirconia, calcium carbonate, and barium sulfate.

[0055] The average particle size of the particles is preferably 10 μm or less. More preferably, it is 1 μm or more and 8 μm or less, even more preferably, it is 2 μm or more and 6 μm or less, and most preferably, it is 3 μm or more and 5 μm or less. A particle size greater than 10 μm is undesirable because it causes particle shedding, resulting in a decrease in scratch resistance. A particle size less than 1 μm is undesirable because it has little effect on uniforming the surface. Furthermore, the amount of particles added is preferably 0.5 parts by mass or more and 10 parts by mass or less per 100 parts by mass of the ionizing radiation curable resin. More preferably, the amount of particles added is 2 parts by mass or more and 8 parts by mass or less, even more preferably, it is 2 parts by mass or more and 6 parts by mass or less, and most preferably, it is 4 parts by mass or more and 5 parts by mass or less. By containing the above-mentioned amount of particles, the surface protective layer 5 can form a uniform surface condition, which is preferable.

[0056] Here, the "particle size (average particle size)" may be a value (average value) obtained by measuring the particle size distribution of the particles used, or may be a value obtained by averaging the particle sizes of multiple particles measured by cross-sectional observation of the resulting decorative material. Although the measurement methods used are different, the resulting particle size values ​​are essentially the same. For example, the average particle size of the particles added to the surface protective layer 5 may be a median diameter (D50) measured using a laser diffraction / scattering particle size distribution analyzer.

[0057] When the entire surface protective layer 5 is cured by UV light, it is necessary to add a photoinitiator to the surface protective layer 5. The photoinitiator is not particularly limited, but examples thereof include benzophenone-based, acetophenone-based, benzoin ether-based, and thioxanthone-based photoinitiators. Functional additives such as antibacterial agents and antifungal agents can also be added to the surface protective layer 5 to impart required functions. Furthermore, an ultraviolet absorber and a light stabilizer can also be added to the surface protective layer 5 as needed. It is common to add any combination of ultraviolet absorbers such as benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based ones, and light stabilizers such as hindered amine-based ones.

[0058] Such decorative sheet 1 has a gloss level of 5.0 or less, despite not containing a gloss adjuster (matt additive), resulting in an extremely low gloss. In conventional decorative sheets, when a decorative sheet having a surface protective layer has a gloss level of 8 or less, the gloss adjuster content in the surface protective layer is high, causing the surface protective layer to become cloudy. This can result in the color and pattern of the colored / patterned layer not being clearly expressed, or the design of the decorative sheet being reduced. Furthermore, when attempting to obtain a decorative sheet with a gloss level close to 0, the gloss adjuster content in the surface protective layer is even higher, making it difficult to form a smooth surface protective layer without streaks or unevenness during formation of the surface protective layer. Decorative sheet 1 can be obtained with a low gloss level of 5.0 or less while maintaining performance comparable to that of a decorative sheet with a gloss level of 20 or more. Here, "gloss level" refers to a measured value measured at an incident angle of 60 degrees using a gloss meter conforming to JIS Z8741.

[0059] <Concealing Layer 8> Furthermore, if it is desired to provide the decorative sheet 1 with concealing properties for the substrate B, this can be achieved by using a colored sheet for the base layer 2 or by providing a separate opaque concealing layer 8. The concealing layer 8 can basically be made of the same material as the pattern layer 3, but since the purpose is concealment, it is preferable to use, for example, an opaque pigment, titanium oxide, iron oxide, or the like as a pigment. Furthermore, to improve concealing properties, it is also possible to add metals such as gold, silver, copper, and aluminum. Generally, flake aluminum is often added.

[0060] (Manufacturing Method) A manufacturing example of the decorative sheet 1 will be described. A resin film is used as the raw fabric layer 2, and a water-resistant protective layer 9 is formed by printing on the upper surface of the raw fabric layer 2. Furthermore, a surface protective layer 5 is formed by printing on the upper surface of the water-resistant protective layer. The surface protective layer 5 is formed by irradiating the surface of an applied ionizing radiation curable resin with light (first irradiation light) having a wavelength of 200 nm or less to shrink the surface of the ionizing radiation curable resin. Subsequently, to cure the shrunk ionizing radiation curable resin, ionizing radiation or UV light having a wavelength longer than the first irradiation light having a wavelength of 200 nm or less is irradiated. In this manner, a decorative sheet 1 is formed, which includes a surface protective layer 5 having a core portion 5A and a ridge portion 5B protruding in a ridge-like manner from one surface (upper surface) of the core portion 5A.

[0061] The present embodiment is not limited to the above embodiment. For example, in order to cure the shrunk ionizing radiation curable resin, ionizing radiation or UV light having a wavelength longer than the first irradiation light having a wavelength of 200 nm or less may be irradiated only once. In this case, the integrated light amount of the first irradiation light having a wavelength of 200 nm or less may be 0.5 mJ / cm. ２ More than 200mJ / cm ２ The following may also be used.

[0062] (Functions and Others) The decorative sheet 1 according to this embodiment includes a surface protective layer 5 having an uneven surface. This configuration allows the gloss (gloss level) of the surface protective layer to be adjusted without including a gloss adjuster (matt additive) in the surface protective layer. Gloss adjusters reduce the oil repellency of layers formed from resin materials, making them more susceptible to fingerprints. Because the surface protective layer 5 according to this embodiment does not include a gloss adjuster, it does not absorb oil and has relatively improved oil repellency. Therefore, in various situations, such as during on-site construction, furniture assembly, and in the daily lives of residents, fingerprints are less likely to adhere to the decorative sheet 1 having the surface protective layer 5.

[0063] Furthermore, a surface protective layer 5 having an uneven surface configuration improves the oil repellency of the surface protective layer 5, making it possible to suppress oil stains and adsorption of contaminants onto the surface of the decorative sheet 1. Furthermore, a surface protective layer 5 having no gloss adjusting agent prevents the particles of the gloss adjusting agent from falling off when the surface of the decorative sheet 1 is scratched, making it possible to make the surface of the decorative sheet 1 less susceptible to changes in gloss and scratches.

[0064] In this embodiment, the surface protective layer 5 is formed as a single layer, but is not limited to this configuration. For example, the surface protective layer 5 may be formed as a multilayer. That is, the surface protective layer 5 may be formed by laminating multiple layers of the same ionizing radiation curable resin or multiple layers of different ionizing radiation curable resins, thereby forming an uneven surface. When multiple layers of different ionizing radiation curable resins are laminated, for example, the outermost layer of the surface protective layer 5 is primarily made of an ionizing radiation curable resin, and the ionizing radiation curable resin is primarily a trifunctional acrylic resin containing a repeating structure, and the repeating structure is preferably one of ethylene oxide, propylene oxide, and ε-caprolactone structures, and the number of repeats of the repeating structure is 3 or more. The layer located on the raw fabric layer 2 side of the surface protective layer 5 (i.e., the layer located below the outermost layer of the surface protective layer 5) is not particularly limited.

[0065] [Examples] Examples based on the present invention will be described below. Example 1 An olefin film (manufactured by Riken Technos Corporation) with a thickness of 55 μm was used as a base layer, one side of the base layer was subjected to a corona treatment, and the following water-resistant protective layer coating liquid was applied to that side. The water-resistant protective layer coating liquid was then dried and cured to form a water-resistant protective layer 9. Subsequently, the following surface protective layer coating liquid was applied on top of the water-resistant protective layer 9. The layer thickness of the surface protective layer coating liquid was set to 5 μm. Thereafter, a Xe excimer lamp with a wavelength of 172 nm was irradiated onto the surface of the surface protective layer coating liquid with an integrated light intensity of 100 mJ / cm. ２ Subsequently, the sheet was irradiated with 100 kGy of ionizing radiation to harden the coating liquid for the surface protective layer, thereby forming a surface protective layer 5, and a decorative sheet of Example 1 having a total thickness of 60 μm was obtained.

[0066] (Water-resistant protective layer coating liquid) The water-resistant protective layer coating liquid was prepared by blending the following curing component with the following aqueous emulsion resin: Water-based emulsion resin Type: Acrylic resin Product name: SETAQUA6776 (manufactured by Allnex Co., Ltd.) Blend: 100 parts by weight Curing component Type: Epoxy resin Product name: EX-810 (manufactured by Nagase ChemteX Corporation) Blend: 5 parts by weight

[0067] (Coating liquid for surface protective layer) The coating liquid for surface protective layer was prepared by blending the following particles with the following ionizing radiation curable resin. Ionizing radiation curable resin Type: trimethylolpropane EO-modified triacrylate (EO 6 moles added) Product name: Miramer M3160 (manufactured by Miwon) Blending amount: 100 parts by mass Particles Product name: Sylysia 250N (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 5 μm Blending amount: 0.5 parts by mass

[0068] Example 2 A decorative sheet of Example 2 was obtained in the same manner as in Example 1, except that the ionizing radiation curable resin contained in the coating liquid for the surface protective layer of Example 1 was replaced with the following: Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (EO 15 moles added) Product name: SR9035 (manufactured by Sartomer)

[0069] Example 3 A decorative sheet of Example 3 was obtained in the same manner as in Example 1, except that the ionizing radiation curable resin contained in the coating liquid for the surface protective layer of Example 1 was replaced with the following: Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (3 EO moles added) Product name: Miramer M3130 (manufactured by Miwon Co., Ltd.)

[0070] Example 4 A decorative sheet of Example 4 was obtained in the same manner as in Example 1, except that the ionizing radiation curable resin contained in the coating liquid for the surface protective layer of Example 1 was replaced with the following: Ionizing radiation curable resin Type: Trimethylolpropane PO-modified triacrylate (6 moles of PO added) Product name: NK Ester A-TMPT-6PO (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0071] Example 5 A decorative sheet of Example 5 was obtained in the same manner as in Example 1, except that the ionizing radiation curable resin contained in the surface protective layer coating liquid of Example 1 was replaced with the following: Ionizing radiation curable resin Type: Caprolactone-modified tris(2-acryloxyethyl) isocyanurate (3 moles of caprolactone (CL) added) Product name: NK Ester A-9300-3CL (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0072] <Example 6> A decorative sheet of Example 6 having a total thickness of 56 μm was obtained in the same manner as Example 1, except that the layer thickness of the coating liquid for surface protective layer of Example 1 was set to 1 μm. <Example 7> A decorative sheet of Example 7 having a total thickness of 57 μm was obtained in the same manner as Example 1, except that the layer thickness of the coating liquid for surface protective layer of Example 1 was set to 2 μm. <Example 8> A decorative sheet of Example 8 having a total thickness of 75 μm was obtained in the same manner as Example 1, except that the layer thickness of the coating liquid for surface protective layer of Example 1 was set to 20 μm.

[0073] <Example 9> A decorative sheet of Example 9 having a total thickness of 80 μm was obtained in the same manner as Example 1, except that the layer thickness of the coating liquid for surface protective layer of Example 1 was set to 25 μm. <Example 10> A decorative sheet of Example 10 was obtained in the same manner as Example 9, except that the particles of Example 9 were not blended. <Example 11> A decorative sheet of Example 11 was obtained in the same manner as Example 3, except that the particles of Example 3 were not blended.

[0074] Example 12 A decorative sheet of Example 12 was obtained in the same manner as Example 1, except that the particles of Example 1 were replaced with the following: Particles Product name: Sylysia 450 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 8.0 μm Blend amount: 0.5 parts by mass

[0075] Example 13 A decorative sheet of Example 13 was obtained in the same manner as Example 1, except that the particles of Example 1 were replaced with the following: Particles Product name: Sylysia 780 (manufactured by Fuji Silysia Chemical Ltd.) Particle size: 11.3 μm Blend amount: 0.5 parts by mass

[0076] <Example 14> A decorative sheet of Example 14 was obtained in the same manner as Example 1, except that the blending amount of the particles of Example 1 was 10 parts by mass. <Example 15> A decorative sheet of Example 15 was obtained in the same manner as Example 1, except that the blending amount of the particles of Example 1 was 11 parts by mass. <Example 16> A decorative sheet of Example 16 having a total thickness of 56 μm was obtained in the same manner as Example 1, except that the layer thickness of the coating liquid for surface protection layer of Example 1 was 1 μm and no particles were used.

[0077] <Example 17> A decorative sheet of Example 17 was obtained in the same manner as Example 1, except that the thickness of the waterproof protective layer of Example 1 was changed to 1 μm. <Example 18> A decorative sheet of Example 18 was obtained in the same manner as Example 1, except that the ionizing radiation curable resin of Example 1 was replaced with the following and the film thickness was changed to 25 μm. Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (EO 50 mol added)

[0078] [Comparative Examples] <Comparative Example 1> A decorative sheet of Comparative Example 1 was obtained in the same manner as in Example 1, except that the step of irradiating the surface of the coating liquid for surface protective layer of Example 1 with a Xe excimer lamp was not performed and the amount of particles was set to 15 parts by mass. <Comparative Example 2> A decorative sheet of Comparative Example 2 was obtained in the same manner as in Example 1, except that the ionizing radiation curable resin contained in the coating liquid for surface protective layer of Example 1 was replaced with the following: Ionizing radiation curable resin Type: ethylene glycol diacrylate (9 moles of EO added) Product name: Light Acrylate 9EG-A (manufactured by Kyoeisha Chemical Co., Ltd.)

[0079] Comparative Example 3 A decorative sheet of Comparative Example 3 was obtained in the same manner as in Example 1, except that the ionizing radiation curable resin contained in the coating liquid for surface protective layer of Example 1 was replaced with the following: Ionizing radiation curable resin Type: pentaerythritol tetraacrylate (35 moles of EO added) Product name: NK Ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) Comparative Example 4 A decorative sheet of Comparative Example 4 was obtained in the same manner as in Example 1, except that the ionizing radiation curable resin contained in the coating liquid for surface protective layer of Example 1 was replaced with the following: Ionizing radiation curable resin Type: trimethylolpropane triacrylate Product name: NK Ester A-TMPT (manufactured by Shin-Nakamura Chemical Co., Ltd.)

[0080] <Comparative Example 5> A decorative sheet of Comparative Example 5 was obtained in the same manner as in Example 1, except that the waterproof protective layer of Example 1 was not provided. <Comparative Example 6> A decorative sheet of Comparative Example 6 was obtained in the same manner as in Example 1, except that the ionizing radiation curable resin of Example 1 was replaced with the following and the film thickness was changed to 20 μm. Ionizing radiation curable resin Type: Trimethylolpropane EO-modified triacrylate (EO 60 moles added)

[0081] [Evaluation] Evaluation was carried out on the decorative sheets obtained by the above-mentioned method in Examples 1 to 18 and Comparative Examples 1 to 6. In these examples, evaluations of "○" and "△" were deemed acceptable since there were no problems in actual use.

[0082] <Surface condition> The surface condition was evaluated visually for uniformity of the surface. The evaluation criteria were as follows: ◯: Uniform surface condition Δ: Some uneven areas present ×: Uneven surface condition over the entire surface

[0083] <Glossiness> The glossiness was measured at 60 degrees using a Rhopoint IQ (manufactured by Konica Minolta, Inc.) A glossiness of 15 or less is visually recognized as being sufficiently low gloss, and therefore, in this example, a glossiness of "15 or less" was deemed acceptable.

[0084] <Fingerprint Resistance: Wipeability Evaluation> Fingerprint wiping ability was evaluated as an evaluation of fingerprint resistance. The glossiness at 60 degrees on the surface of each decorative sheet was measured and recorded as [initial glossiness]. Next, a fingerprint resistance evaluation liquid was applied to the surface protective layer, and then the fingerprint resistance evaluation liquid applied to the decorative sheet surface was wiped off. The glossiness at 60 degrees on the area from which the fingerprint resistance evaluation liquid had been wiped off was then measured and recorded as [glossiness after wiping]. Here, a higher fatty acid was used as the fingerprint resistance evaluation liquid. The fingerprint wiping rate was calculated as follows: Fingerprint wiping rate (%) = (glossiness after wiping / initial glossiness) x 100 The evaluation criteria were as follows: ◯: 70% or more and less than 250% Δ: 50% or more and less than 70%, or 250% or more and less than 300% ×: Less than 50%, or 300% or more

[0085] <Stain Resistance> To evaluate stain resistance, a 10 mm wide line was drawn using blue ink, black quick-drying ink, and red crayon according to the Stain A Test specified in the Japanese Agricultural Standards (JAS), and after leaving it for 4 hours, the blue ink, black quick-drying ink, and red crayon lines were wiped off with a cloth soaked in ethanol to evaluate stain resistance by ink. The evaluation criteria were as follows: ◯: Lines of each color could be easily wiped off Δ: Part of each line of each color could be wiped off, but some stains remained ×: Lines of each color could not be wiped off

[0086] <Scratch Resistance Test: Steel Wool Rubbing Test> The resulting decorative sheet was attached to wood substrate B using a urethane adhesive, and then a steel wool rubbing test was carried out to evaluate scratch resistance. A load of 100 g was applied to the steel wool and the sheet was rubbed back and forth 20 times, and the surface of the decorative sheet was visually inspected for scratches and changes in gloss. The evaluation criteria were as follows: ◯: No scratches or changes in gloss occurred on the surface Δ: Minor scratches or changes in gloss occurred on the surface ×: Significant scratches or changes in gloss occurred on the surface

[0087] <Bending Workability Test> The obtained decorative sheet was attached to the wooden substrate B using a urethane adhesive, with the surface of the base layer (i.e., the back surface of the decorative sheet) facing the wooden substrate B. After that, a V-shaped groove was made up to the boundary where the wooden substrate B and the decorative sheet 1 were bonded together, so as not to scratch the decorative sheet. Next, the wooden substrate B was bent 90 degrees along the V-shaped groove so that the surface of the decorative sheet facing the surface protection layer (i.e., the surface of the decorative sheet) formed a mountain fold, and the bent portion of the surface of the decorative sheet was observed using an optical microscope to check for whitening or cracks, and the state of bending workability was evaluated. The evaluation criteria were as follows: ◯: No whitening or cracks were observed △: Whitening was observed in some areas ×: Whitening was observed over the entire surface, or cracks were observed in some areas

[0088] <Water Resistance Test> Approximately 1 ml of water was dropped onto the resulting decorative sheet, and after covering it with a watch glass and leaving it for 1 hour, it was wiped off and the change in gloss on the surface of the decorative sheet was visually confirmed. The evaluation criteria were as follows: ◯: No change in gloss was observed. Δ: A slight change in gloss occurred on the surface. ×: A significant change in gloss occurred on the surface.

[0089] The evaluation results are shown in Tables 1 and 2.

[0090]

[0091]

[0092] As shown in Table 1, the decorative sheets of Examples 1 to 18 can provide decorative sheets that have low gloss while also having fingerprint resistance, scratch resistance, contamination resistance, bending processability, and water resistance. In addition to the surface shape and resin composition of the surface protective layer, further performance improvements can be achieved by optimizing the thickness of the surface protective layer and the particle size and amount of particles added.

[0093] The present invention can also be configured, for example, as follows: (1) A decorative sheet comprising a base layer, a water-resistant protective layer, and a surface protective layer laminated in this order, wherein the surface protective layer has an uneven shape with ridge-like protruding portions formed on its surface, wherein the ratio RSm / Ra of the surface roughness index RSm to the surface roughness index Ra of the uneven shape of the surface protective layer is within the range of 10 to 300, wherein the surface protective layer is mainly made of an ionizing radiation curable resin, wherein the ionizing radiation curable resin is mainly composed of a trifunctional acrylic resin containing a repeating structure, and wherein the number of repetitions of the repeating structure is 3 or more. (2) The decorative sheet according to (1) above, wherein the main material of the resin component constituting the water-resistant protective layer is a thermosetting resin, wherein the thermosetting resin contains a resin having a crosslinked structure formed from a coating liquid containing an acrylic resin as a resin component and an epoxy compound as a curing component. (3) The decorative sheet according to (1) or (2) above, wherein the repeating unit structure is any one of ethylene oxide, propylene oxide, and ε-caprolactone. (4) The decorative sheet according to any one of (1) to (3) above, wherein the thickness of the surface protective layer is within the range of 2 μm to 20 μm. (5) The decorative sheet according to any one of (1) to (4) above, wherein the thickness of the water-resistant protective layer is within the range of 2 μm to 10 μm. (6) The decorative sheet according to any one of (1) to (5) above, wherein the surface protective layer contains particles having an average particle size of 10 μm or less. (7) The decorative sheet according to (6) above, wherein the amount of the particles added is within the range of 0.5 parts by mass to 10 parts by mass per 100 parts by mass of the ionizing radiation curable resin. (8) The decorative sheet according to any one of (1) to (7) above, wherein the gloss level of the surface protective layer is 5.0 or less. (9) The decorative sheet according to any one of (1) to (8), wherein the surface protective layer comprises a core portion and the ridge portion formed on the core portion, and the ratio of the layer thickness of the ridge portion to the layer thickness of the core portion (layer thickness of the ridge portion / layer thickness of the core portion) is within the range of 0.01 to 2.0.(10) The decorative sheet according to (9) above, wherein the ratio of the layer thickness of the ridge portion to the layer thickness of the core portion (ridge portion layer thickness / core portion layer thickness) is within the range of 0.1 or more and 1.0 or less. (11) The decorative sheet according to any one of (1) to (10) above, wherein the ratio RSm / Ra of the uneven shape of the surface protective layer is within the range of 80 or more and 150 or less. (12) The decorative sheet according to any one of (1) to (11) above, wherein the cross-sectional shape of the ridge portion in the thickness direction of the surface protective layer is a sinusoidal wave shape. (13) The decorative sheet according to any one of (1) to (12) above, wherein the trifunctional acrylic resin is a resin composed of glycerin triacrylate, isocyanurate triacrylate, or pentaerythritol triacrylate. (14) A method for producing a decorative sheet according to any one of (1) to (13) above, characterized in that the surface of a coated ionizing radiation curable resin is irradiated with light having a wavelength of 200 nm or less, and then irradiated with ionizing radiation or UV light having a wavelength longer than the light having a wavelength of 200 nm or less, thereby forming a surface protective layer having ridge-like protruding portions. (15) A method for producing a decorative sheet according to (14) above, characterized in that the light having a wavelength of 200 nm or less has a wavelength of 172 nm. (16) A method for producing a decorative sheet according to any one of (1) to (13), characterized in that the surface of the ionizing radiation curable resin is irradiated with light having a wavelength of 200 nm or less, and then irradiated once with ionizing radiation or UV light having a wavelength longer than the light having a wavelength of 200 nm or less, thereby forming the surface protective layer having the ridge-like protruding portions, and the integrated light amount of the light having a wavelength of 200 nm or less is 0.15 mJ / cm. ２ More than 200mJ / cm ２ The method for producing a decorative sheet according to (14) or (15) above, characterized in that the integrated light amount of UV light having a wavelength longer than that of light having a wavelength of 200 nm or less is within the following range: (17) The integrated light amount of UV light having a wavelength longer than that of light having a wavelength of 200 nm or less is 10 mJ / cm ２ More than 500mJ / cm ２(16) A method for producing a decorative sheet according to (16) above, characterized in that the viscosity of the ionizing radiation curable resin is within the following range: (18) A method for producing a decorative sheet according to any one of (14) to (17) above, characterized in that the surface of an applied ionizing radiation curable resin is irradiated with light having a wavelength of 200 nm or less, and then irradiated with only the ionizing radiation, thereby forming a surface protective layer having the ridge-like protruding portions. (19) A method for producing a decorative sheet according to any one of (14) to (18) above, characterized in that the viscosity of the ionizing radiation curable resin is in the range of 10 mPa·s or more and 500 mPa·s or less.

[0094] DESCRIPTION OF SYMBOLS 1 Decorative sheet 2 Base layer 3 Design layer 4 Transparent resin layer 5 Surface protective layer 6 Primer layer 7 Adhesive layer 8 Shielding layer 9 Water-resistant protective layer 11 Decorative material B Substrate

Claims

1. A base layer, a waterproof protective layer, and a surface protective layer are laminated in this order, The surface protection layer has an uneven surface having ridge-like protrusions formed thereon, a ratio RSm / Ra of a surface roughness index RSm of the uneven shape of the surface protective layer to a surface roughness index Ra is within a range of 10 or more and 300 or less, The surface protective layer is mainly made of an ionizing radiation curable resin, The ionizing radiation curable resin is a trifunctional acrylic resin containing a repeating unit as a main component, A decorative sheet characterized in that the repeating structure is repeated three or more times.

2. The main material of the resin component constituting the water-resistant protective layer is a thermosetting resin, 2. The decorative sheet according to claim 1, wherein the thermosetting resin comprises a resin having a crosslinked structure formed by a coating liquid containing an acrylic resin as a resin component and an epoxy compound as a curing component.

3. 3. The decorative sheet according to claim 1, wherein the repeating unit structure is any one of ethylene oxide, propylene oxide, and ε-caprolactone structures.

4. 3. The decorative sheet according to claim 1, wherein the thickness of the surface protective layer is within a range of 2 μm to 20 μm.

5. 3. The decorative sheet according to claim 1, wherein the thickness of the waterproof protective layer is within a range of 2 μm to 10 μm.

6. 3. The decorative sheet according to claim 1, wherein the surface protective layer contains particles having an average particle size of 10 μm or less.

7. 7. The decorative sheet according to claim 6, wherein the amount of said particles added is within a range of 0.5 parts by mass to 10 parts by mass with respect to 100 parts by mass of said ionizing radiation curable resin.

8. 3. The decorative sheet according to claim 1, wherein the surface protective layer has a glossiness of 5.0 or less.

9. the surface protection layer includes a core portion and the ridge portion formed on the core portion, 3. The decorative sheet according to claim 1, wherein the ratio of the layer thickness of the ridge portion to the layer thickness of the core portion (layer thickness of the ridge portion / layer thickness of the core portion) is within a range of 0.01 to 2.

0.

10. 10. The decorative sheet according to claim 9, wherein the ratio of the layer thickness of the ridge portion to the layer thickness of the core portion (layer thickness of the ridge portion / layer thickness of the core portion) is within a range of 0.1 to 1.

0.

11. 3. The decorative sheet according to claim 1, wherein the ratio RSm / Ra of the uneven shape of the surface protective layer is within a range of 80 or more and 150 or less.

12. 3. The decorative sheet according to claim 1, wherein a cross-sectional shape of the ridge portion in the thickness direction of the surface protective layer is a sine wave shape.

13. 3. The decorative sheet according to claim 1, wherein the trifunctional acrylic resin is a resin composed of glycerin triacrylate, isocyanurate triacrylate, or pentaerythritol triacrylate.

14. A method for producing the decorative sheet according to claim 1 or 2, The surface of the applied ionizing radiation curable resin is irradiated with light having a wavelength of 200 nm or less, and then irradiated with ionizing radiation or UV light having a wavelength longer than the light having a wavelength of 200 nm or less, A method for producing a decorative sheet, comprising forming a surface protective layer having ridge-like protruding portions.

15. The method for producing a decorative sheet according to claim 14, wherein the light having a wavelength of 200 nm or less has a wavelength of 172 nm.

16. The surface of the ionizing radiation curable resin is irradiated with light having a wavelength of 200 nm or less, and then irradiated once with ionizing radiation or UV light having a wavelength longer than the light having a wavelength of 200 nm or less. forming the surface protection layer having the ridge portion; The integrated light amount of the light having a wavelength of 200 nm or less is 0.15 mJ / cm ２ More than 200mJ / cm ２ The method for producing a decorative sheet according to claim 14, characterized in that the range is as follows:

17. The integrated amount of UV light having a wavelength longer than the light having a wavelength of 200 nm or less is 10 mJ / cm ２ More than 500mJ / cm ２ The method for producing a decorative sheet according to claim 16, characterized in that the range is as follows:

18. The surface of the applied ionizing radiation curable resin is irradiated with light having a wavelength of 200 nm or less, and then irradiated with only the ionizing radiation, The method for producing a decorative sheet according to claim 14, further comprising forming a surface protective layer having ridge-like protruding portions.

19. 15. The method for producing a decorative sheet according to claim 14, wherein the viscosity range of the ionizing radiation curable resin is from 10 mPa·s to 500 mPa·s.